Effect Of A Small Amount Of Copper In Medium-carbon Steel

This shows the result of tests by C. R. Hayward and A. B. Johnston
on two types of steel: one containing 0.30 per cent carbon, 0.012
per cent phosphorus, and 0.860 per cent copper, and the other 0.365
per cent carbon, 0.053 per cent phosphorus, and 0.030 per cent
copper. The accompanying chart in Fig. 13 shows that high-copper
steel has decided superiority in tensile strength, yield point and
ultimate strength, while the ductility is practically the same.
Hardness tests by both methods show high-copper steel to be harder
than low-copper, and the Charpy shock tests show high-copper steel
also superior to low-copper. The tests confirm those made by Stead,
showing that the behavior of copper steel resembles that of nickel
steel. The high-copper steels show finer grain than the low-copper.
The quenched and drawn specimens of high-copper steel were found
to be slightly more martensitic.